Hydroaminoalkylation of unactivated olefins with dialkylamines.
The intermolecular addition of the alpha-C-H bonds of unactivated dialkylamines to unactivated olefins in the presence of the chloro amido complex [TaCl3(NEt2)2]2 (2) is described. This process forms the branched insertion products in high yields (up to 96%) and selectivities, and represents a rare example of an intermolecular amine-olefin coupling reaction that does not require preactivation of either substrate. The reaction is shown to encompass the addition of the primary C-H bonds in linear- and branched-methylamines, as well as secondary C-H bonds in higher dialkylamines. The related chloroanilido complex [TaCl3(NMePh)2]2 (4) is also shown to catalyze the addition of N-alkyl-arylamines to olefins at temperatures as low as 90 degreesC. 1H NMR spectroscopy, identification of the catalyst structure, and deuterium-labeling experiments all suggest that reactions catalyzed by 2 and 4 occur by turnover-limiting generation of an eta2-imine complex. These labeling studies also imply that more favorable partitioning of the eta2-imine complex toward reaction with alkene versus regeneration of the starting bis-amido complex accounts for the higher reactivity of the mixed halide amido catalyst versus a homoleptic amido complex.
Herzon
Seth B
SB
Department of Chemistry, University of Illinois, 600 South Mathews Avenue, Urbana, Illinois 61801, USA.
Hartwig
John F
JF
D000475:Alkenes / Q000737:chemistry*; D000478:Alkylation; D000577:Amides / Q000737:chemistry; D000586:Amination; D000588:Amines / Q000138:chemical synthesis* / Q000737:chemistry*; D000813:Anilides / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry; D007097:Imines / Q000737:chemistry; D013635:Tantalum / Q000737:chemistry
D000475:Alkenes; D000577:Amides; D000588:Amines; D000813:Anilides; D002712:Chlorides; D007097:Imines; C437166:tantalum chloride; D013635:Tantalum